the current chief is hiring is passing on the first batch of finalists to replace moore. >> police are blaming much of the violence on two groups of criminals but not calling gangs. since friday, 15 people have been shot at nine locations. four people were killed. abc 7 news is live in the oakland police headquarters tonight with the late yeflt on this story. nick? >> good evening. new information obtained just minutes ago. abc 7 news can confirm that four people have been arrested in connections to shoogts. , my of them are related to the operation cease-fire. >> this group has become increasingly violent.tádwe they've grown in numbers. >> police chief says there is evidence tying two groups to shootings over the weekend saying he works hard to make sure there are not more. >> i took swift action by reassigning officers to areas where retaliation was we thought was to occur. >> he believes those groups are responsible for 90% of the violence in oakland. >> talking about murders. robberies and shooting autos sl have been 15 victims of gunfire in oakland. sky 7 over east 17th street. p